Submission #269828

#	Time	Username	Problem	Language	Result	Execution time	Memory
269828		egekabas	XOR Sum (info1cup17_xorsum)	C++14	18 / 100	1681 ms	34868 KiB

xorsum

#include <bits/stdc++.h>
#define all(x) (x).begin(), (x).end()
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<ll, ll> pll;
typedef pair<ull, ull> pull;
typedef pair<int, int> pii;
typedef pair<ld, ld> pld;
int ans = 0;
map<int, int> mpp;
int n;
vector<int> v;
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    
    //freopen("in.txt", "r", stdin);
    //freopen("out.txt", "w", stdout);

    cin >> n;
    while(n--){
        int tmp;
        cin >> tmp;
        mpp[tmp]++;
    }
    for(auto u : mpp){
        if((u.ss-1)%4 == 0 || u.ss%4 == 2){
            ans ^= 2*u.ff;
        }
        if(u.ss%2)
            v.pb(u.ff);
    }
    n = v.size();
    for(int i = 0; i < n; ++i)
        for(int j = i+1; j < n; ++j)
            ans ^= v[i]+v[j];
    cout << ans << '\n';
}

• Subtask 1: 7 / 7
• Subtask 2: 11 / 11
• Subtask 3: 0 / 21
• Subtask 4: 0 / 38
• Subtask 5: 0 / 23